I have all three monitors working fine. I even have the panel showing on the center monitor like I want, but when I open a new window it always shows up on the left monitor. I often turn off the side monitors and use only the center so that is exceptionaly anoying as it means I must turn the thing on, then drag the window tothe middle monitor and then turn it back off. Also not sure if it is the same or not but the login screen shows mirrored on the center and left only, (not a huge problem) but the unlock box when waking from screen saver/blank screen always shows on the left only. (which is a bit more of a pain.) on mint 15 / cinnamon

Can't remember but under older 1.8 But Cinnamon 2.0 has a Set Primary button.

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Next to the On button. So select display and set as primary.
But that will also likely change where your menu bar is presently which is on Center monitor?
And don't know state of Cinnamon anymore if you can or have to move the panel to preferred monitor?
Maybe someone actually using Cinnamon now can chime in with more info.

As now I'm on KDE as that is also a major issue for me. As have 3 Virtual workspaces on Dual 22" displays.
So having to drag and adjust size for 6-8 apps every time is a pain. KDE has that built in where every app has "Remember Size & Position"
Never understood linux users accepting having to drag and resize their apps every time.
Really slows production down for me as don't like or use tiling myself as some apps are custom sized and positioned with others.
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